एक खगोलीय अपवर्ती दूरदर्शी (Refracting Telescope) में मुख्य रूप से कितने उत्तल लेंस होते हैं?

The Dandi March, also known as the Salt Satyagraha, was led by which influential leader?

Which act formally granted independence to India, marking the end of British rule?

Who was the key figure in establishing the Indian National Congress?